•Exclusion, sterilisation and disruption offer a different paradigm in pest management.•Exclusion (netting) can be used in the most diverse settings.•Sterile insect release (SIT) is the most ...selective but also costly.•Mating disruption is the easiest to implement at the farm level.
Because of their perennial nature, orchards harbor one of the most complex ecosystems in agriculture. Nevertheless, crop protection programs still mainly focus on pesticides (synthetic or organic-approved) to prevent or limit the action of so-called noxious species in these systems. Killing agents represent the dominant paradigm and have been used in agriculture for decades. This paper synthesizes the available literature about the other approaches, more suited to organic farming, which recognize that the radicalness of killing is not necessary to prevent crop losses. Exclusion barriers represent one of the most readily available means of protecting the crop that way, but other behavior-based techniques have been developed, such as sterile insect technique and mating disruption. While there are many other possibilities, these are the three approaches that are currently getting the most interest in tree fruit production, due to ecological and agronomical characteristics, some of which will be detailed in this review.
To improve exclusion systems for fruit trees, insect nets of various types were evaluated for their permeability to different beneficial and pest species, under laboratory and field conditions. Pests ...studied were the apple maggot,
Rhagoletis pomonella
(Diptera: Tephritidae) and the spotted wing drosophila,
Drosophila suzukii
(Diptera: Drosophilidae). Beneficials were
Aphidoletes aphidimyza
(Diptera: Cecidomyiidae),
Aphidius matricariae
(Hymenoptera: Braconidae) and
Aphelinus abdominalis
(Hymenoptera: Aphelinidae). Mesh nets with five different apertures (square, rectangle, triangle, rhombus and hexagon) and six different sizes (from 0.4 to 2.8 mm) were 3D-printed from strands of polylactic acid and tested in the laboratory along with two commercially available nets made of polyethylene. The physical and behavioral characteristics of the six studied species affected their ability to cross the nets. For an equal size (open area), the intrusion rate was generally greater through the square- and/or hexagonal-shaped meshes. Rectangular-shaped apertures totally excluded the apple maggot in both laboratory and field trials, provided their shortest side did not exceed 1.9 mm. For the spotted wing drosophila, a maximum of 1.0 mm was similarly required for exclusion in the laboratory. The shape factor (length/width ratio) of the apertures appeared to affect net selectivity. Field trials confirmed that more aphid predators and leafroller parasitoids colonized trees covered with larger mesh nets (2.3 × 3.4 mm), while still excluding the apple maggot. Thus, for a similar aperture size (area), an elongated rectangular-shaped mesh appears to facilitate access for beneficials, while continuing to provide effective protection against apple pests.
The zoophytophagous mullein bug, Campylomma verbasci (Meyer-Dür) (Hemiptera: Miridae), is a beneficial predator of mites and aphids, but also a pest causing damage when it feeds on apples. The aim of ...this study was to evaluate three different parameters of phytophagy of the mullein bug both in laboratory (phytophagous behavior) and field (fruit damage) tests: 1) apple cultivar, 2) fruit size, and 3) nymphal instar. In the laboratory, nymphs were observed individually for 15 min in Petri dishes containing agar gel and an apple fruitlet to evaluate feeding punctures of four apple cultivars, four fruit sizes, and five nymphal instars. In the orchard, nymphs were caged at bloom in sleeve cages to evaluate damage on the developing fruit of seven apple cultivars and three nymphal instars on 'Red Delicious'. The feeding punctures in the laboratory were higher on 'Red Delicious' than on 'Honeycrisp'; fruit damage in the orchard did not differ among cultivars at mid-season, but was higher on 'Red Delicious' than on 'Lobo' and 'Marshall McIntosh' at harvest. The number of feeding punctures in the laboratory was higher on 7-9 mm than on 18-20 mm size fruit for 'Red Delicious', but not for 'Honeycrisp'. The number of feeding punctures in the laboratory made by the fifth nymphal instar was higher than those made by younger nymphs, but fruit damage in the orchard did not differ among nymphal instars. Our results will help to elaborate a management chart for this insect by minimizing risks and promoting its use for biocontrol.
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La punaise de la molène, Campylomma verbasci (Meyer-Dür) (Hemiptera: Miridae), est un prédateur bénéfique zoophytophage des acariens et pucerons dans les vergers, mais également un ravageur causant des dommages lorsqu'il se nourrit sur les pommes. Le but de cette étude était d'évaluer trois paramètres différents sur la phytophagie de la punaise de la molène, à la fois en laboratoire (comportement phytophage) et sur le terrain (dommages aux fruits) : 1) les cultivars de pommes, 2) la taille des fruits, et 3) les stades larvaires. En laboratoire, les larves étaient observées individuellement pendant 15 min dans des boites de Petri contenant un gel d'agar et une jeune pomme afin de déterminer les piqûres de nutrition sur quatre cultivars de pommes, quatre tailles de fruit et cinq stades larvaires différents. En verger, des larves ont été encagées à la floraison dans des manchons en mousseline afin d'évaluer les dommages sur les fruits en développement. Les essais ont été effectués sur sept cultivars de pommes ainsi qu'avec trois stades larvaires sur le cultivar "Délicieuse rouge". Les piqûres de nutrition en laboratoire étaient plus nombreuses sur "Délicieuse rouge" que sur "Honeycrisp"; les dommages aux fruits en verger ne différaient pas entre les cultivars à mi-saison, mais étaient plus nombreux sur "Délicieuse rouge" que sur "Lobo" et "Marshall McIntosh" à la récolte. Les piqûres de nutrition en laboratoire étaient plus nombreuses pour la taille de fruit 7-9 mm que 18-20 mm sur "Délicieuse rouge", mais pas sur "Honeycrisp". Le nombre de piqûres de nutrition (en laboratoire) faites par les larves de stade 5 étaient plus nombreuses que celles faites par les larves plus jeunes, mais les dommages aux fruits (en verger) ne différaient pas entre les stades larvaires. Ces résultats vont aider à élaborer une charte de gestion de cet insecte en minimisant les risques et en favorisant son rôle d'agent de lutte biologique.
Low and medium potency benzodiazepines were initially introduced for the treatment of insomnia and anxiety. Their therapeutic actions as anxiolytics, sedative hypnotics, anticonvulsants, and muscle ...relaxants (with their low toxicity) have led to their use as first-line treatments, and they have become one of the most prescribed classes of drugs. Novel therapeutic uses of benzodiazepines were discovered with the introduction of the high-potency benzodiazepines (e.g., alprazolam, clonazepam, and lorazepam). They were found to be effective in treating panic disorder and panic attacks with or without agoraphobia, as add-on therapy to selective serotonin reuptake inhibitors in the treatment of obsessive-compulsive disorder and panic disorders, and as adjunctive therapy in treating patients with acute mania or acute agitation. High-potency benzodiazepines have replaced low and medium potency benzodiazepines in all benzodiazepine clinical indications due to their greater therapeutic effects and rapid onset of action. Differences in distribution, elimination half-life, and rate of absorption are important considerations when choosing a high-potency benzodiazepine. Typically, a benzodiazepine with long distribution and elimination half-lives is preferred. A maximum dose of 2 mg/day of any of the high-potency benzodiazepines when given for more than 1 week is recommended. Although as a class benzodiazepines act rapidly and are well tolerated, their use presents clinical issues such as dependence, rebound anxiety, memory impairment, and discontinuation syndrome.
In two double-blind trials conducted in North America, 513 patients with chronic schizophrenia received risperidone, haloperidol, or placebo. In the present study, combined data from the two trials ...were analyzed.
Patients were randomly assigned to receive placebo, fixed doses of risperidone (2, 6, 10, and 16 mg/day) or 20 mg/day of haloperidol for 8 weeks. Factor analysis of scores on the Positive and Negative Syndrome Scale (PANSS) produced five dimensions (negative symptoms, positive symptoms, disorganized thought, uncontrolled hostility/excitement, and anxiety/depression), similar to the five dimensions of previous factor-analytic studies of PANSS data.
Mean changes (symptom reductions) in PANSS factor scores from baseline to treatment Weeks 6 and 8 were significantly greater in patients receiving 6-16 mg/day of risperidone than in patients receiving placebo or haloperidol. The advantages of risperidone were greatest for negative symptoms, uncontrolled hostility/excitement, and anxiety/depression. Even at the lowest dose, 2 mg/day, risperidone was significantly (p < or = .05) superior to haloperidol in reducing negative symptoms. The differences in outcomes between risperidone and haloperidol on PANSS scores were not related to extrapyramidal symptoms.
Risperidone produced significantly (p < or = .05) greater improvements than haloperidol on all five dimensions. The large between-group differences on negative symptoms, hostility/excitement, and anxiety/depression suggest that risperidone and other serotonin/dopamine antagonists have qualitatively different effects from those of conventional antipsychotic agents.
Specific trace elements incorporated into the growing surface of the fish otolith reflect the physical and chemical characteristics of the ambient water, although not necessarily in a simplistic ...manner. Since fish which spend at least part of their lives in different water masses often produce otoliths of different elemental composition, the otolith elemental composition (‘elemental fingerprint’) can serve as an environmentally induced tag of groups of fish. On the basis of isotope dilution ICPMS (ID-ICPMS) assays of nearly 2500 dissolved adult cod (
Gadus morhua) otoliths, it has become clear that cod otolith elemental fingerprints based on the elements Li, Mg, Mn, Sr and Ba are physically stable, reproducible and consistent between left and right otoliths. Highly significant differences existed among the fingerprints of all of the spawning aggregations, resulting in a characteristic marker for each aggregation. Long-term stability (4–13 years) of the fingerprints for a given spawning group was not evident, indicating that the fingerprint was not a proxy for genetic identity. However, the fingerprint was very stable over the short-term (up to 1 year), suggesting that it could serve as a seasonally stable biological tracer, or natural tag, of pre-defined groups of fish, even during situations of extensive stock mixing. As an illustration of the tracer approach, a maximum likelihood-based stock mixture analysis was applied to feeding (summer) and over-wintering stock distributions, using the fingerprints of the spring spawning aggregations as known-stock reference samples. The results of the summer stock mixture analyses suggested that the mixture analysis was accurate within 1%, while the stock mixture analysis of the over-wintering schools produced stock-specific distributions which would have been difficult to obtain using alternative approaches. While the use of elemental fingerprints as natural tags is not suited to all stock mixing situations, suitability can probably be determined beforehand on the basis of existing environmental and biological information.
More than 10 years after the collapse of Atlantic cod (Gadus morhua) fisheries in Canada, the role of increased seal populations in the decline and lack of recovery of the stocks continues to be ...discussed. Using removals and abundance indices from synthetic populations, we found that sequential population analysis can uncover trends in natural mortality. We used this approach to examine variation in natural mortality (M) of southern Gulf of St. Lawrence cod. M increased from the late 1970s to the mid-1990s but declined slightly recently. Results were consistent with previous work indicating that M increased in the 1980s. Changes in estimated M for this cod stock matched fluctuations in grey seal (Halichoerus grypus) abundance. The increase in grey seal abundance from the late 1970s to the mid-1990s corresponded with the increase in estimated M of cod over this time period. The correspondence between seal abundance and M of cod supports the hypothesis that seal predation may be a cause of increased M. However, the diet information available suggests that seals consume mainly juvenile cod, whereas our evidence for an increase in M is for larger cod (ages 3 years and older).
Major temporal changes in the importance of euphausiids and Atlantic herring Clupea harengus in the diet of Atlantic cod Gadus morhua, 10-75 cm L sub(F), occurred in shallow waters (<100 m depths) of ...the southern Gulf of St Lawrence between 1959 and 2000. Euphausiids represented 6-70% of prey mass for Atlantic cod 31-60 cm L sub(F) from 1959 to 1987 but only trace amounts were detected in stomachs collected from 1990 to 2000. Mysids and gammarid amphipods (for Atlantic cod less than or equal to 45 cm L sub(F)), and Atlantic herring (for Atlantic cod >45 cm L sub(F)) largely replaced euphausiids in the Atlantic cod diets from 1990 to 2000. This diet change suggested there has been a major perturbation of the food web of the southern Gulf of St Lawrence. The importance of fishes (mostly Atlantic herring) in the diet of Atlantic cod >45 cm L sub(F) increased significantly between the periods 1959-1980 and 1987-2000. Atlantic herring comprised 0-4% (mean 1.3%) of prey mass of Atlantic cod 46-60 cm L sub(F) from 1959 to 1980 and increased to 2-42% (mean 19.6%) of the diet from 1987 to 2000. Atlantic herring comprised 0-25% (mean 9.4%) of the prey mass of Atlantic cod 61-75 cm L sub(F) from 1959 to 1980 and increased to 42-81% (mean 54.2%) of prey mass from 1987 to 2000. This increased consumption of Atlantic herring was consistent with observed changes in abundance of Atlantic herring in the ecosystem between the late 1970s and 2000. The large changes in consumption of euphausiids and Atlantic herring represent highly significant changes and would need to be included in the development and interpretation of ecosystem-based management models for this ecosystem. Crown Copyright Published by Elsevier Science Ltd on behalf of The Fisheries Society of the British Isles. All Rights reserved.
Excessive and unsustainable fishing mortality was the predominant factor in the depletion of Northwest Atlantic cod (Gadus morhua) stocks. However, despite imposition of severe catch restrictions for ...over a decade, stocks have mostly failed to recover at predicted rates. A number of explanations have been considered. Our analysis of demographic characteristics of 12 of these stocks indicates that recent productivity over the northern portion of the range is much lower than 20 years previous when several stocks recovered from less severe declines. Main contributing factors are, in rank order, increased natural mortality, decreased body growth, and in a few cases, reduced recruitment rates. Continued fishing in directed and bycatch fisheries is also an important factor. Under current conditions, we estimate negative or very low (<2% per year) average growth rates in eight stocks. If fishing ceases, growth rates of >5% would be expected in six stocks, with >10% in four of these. Although productivity is low, we conclude that fishing mortality is further delaying recovery.
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